/*
 * Copyright 2023 AntGroup CO., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 */

package com.antgroup.geaflow.dsl.sqlnode;

import com.antgroup.geaflow.dsl.operator.SqlPathPatternOperator;
import java.util.List;
import java.util.Objects;
import org.apache.calcite.sql.SqlCall;
import org.apache.calcite.sql.SqlIdentifier;
import org.apache.calcite.sql.SqlNode;
import org.apache.calcite.sql.SqlNodeList;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.SqlWriter;
import org.apache.calcite.sql.parser.SqlParserPos;
import org.apache.calcite.sql.validate.SqlValidator;
import org.apache.calcite.sql.validate.SqlValidatorScope;
import org.apache.calcite.util.ImmutableNullableList;

public class SqlPathPattern extends SqlCall {

    private SqlNodeList pathNodes;

    private SqlIdentifier pathAlias;


    public SqlPathPattern(SqlParserPos pos, SqlNodeList pathNodes, SqlIdentifier pathAlias) {
        super(pos);
        this.pathNodes = Objects.requireNonNull(pathNodes);
        this.pathAlias = pathAlias;
    }

    @Override
    public SqlOperator getOperator() {
        return SqlPathPatternOperator.INSTANCE;
    }

    @Override
    public List<SqlNode> getOperandList() {
        return ImmutableNullableList.of(pathNodes, pathAlias);
    }

    @Override
    public void validate(SqlValidator validator, SqlValidatorScope scope) {
        validator.validateQuery(this, scope, validator.getUnknownType());
    }

    @Override
    public void setOperand(int i, SqlNode operand) {
        switch (i) {
            case 0:
                this.pathNodes = (SqlNodeList) operand;
                break;
            case 1:
                this.pathAlias = (SqlIdentifier) operand;
                break;
            default:
                throw new IllegalArgumentException("Illegal index: " + i);
        }
    }

    @Override
    public void unparse(SqlWriter writer, int leftPrec, int rightPrec) {
        if (pathAlias != null) {
            pathAlias.unparse(writer, 0, 0);
            writer.print("=");
        }

        for (SqlNode node : pathNodes) {
            node.unparse(writer, leftPrec, rightPrec);
        }
    }

    public SqlNodeList getPathNodes() {
        return pathNodes;
    }

    public String getPathAliasName() {
        if (pathAlias != null) {
            return pathAlias.getSimple();
        }
        return null;
    }

    public void setPathAlias(SqlIdentifier pathAlias) {
        this.pathAlias = pathAlias;
    }

    public SqlMatchNode getFirst() {
        return (SqlMatchNode) pathNodes.get(0);
    }

    public SqlMatchNode getLast() {
        return (SqlMatchNode) pathNodes.get(pathNodes.size() - 1);
    }
}
